Apparatus and method for regenerating odor absorbent in a motor vehicle hvac system

ABSTRACT

An apparatus is provided for regenerating an odor absorbent in a motor vehicle HVAC system. That apparatus includes a regeneration blower assembly that is connected between a heater plenum and a fresh air inlet duct of the HVAC system. Air is drawn from the passenger cabin of the motor vehicle through the heater plenum where that air is warmed. The warmed air is directed through the odor absorbent to remove odors and regenerate the odor absorbent. The warm air and the odors entrained therein is discharged through a fresh air inlet of the HVAC system.

TECHNICAL FIELD

This document relates generally to the motor vehicle equipment fieldand, more particularly, to an apparatus and method for regenerating odorabsorbent in a motor vehicle heating, ventilation and air-conditioning(HVAC) system.

BACKGROUND

Today's motor vehicles are commonly equipped with air filters includingodor absorbent material, such as activated carbon, to trap odors andprevent them from permeating the passenger cabin of the motor vehicle.Under certain conditions, odors previously trapped in the odor absorbentmay outgas into the passenger cabin through the ducts of the HVAC systemso that when the doors are opened and people enter the vehicle,unpleasant odors are present.

This document relates to an apparatus and method for regenerating theodor absorbent in a motor vehicle HVAC system that is also specificallyadapted to push the odors from the regenerated odor absorbent materialoutside the vehicle and into the ambient environment after theowner/occupants have left the vehicle.

SUMMARY

In accordance with the purposes and benefits described herein, anapparatus is provided for regenerating an odor absorbent in a motorvehicle HVAC system. That apparatus may be broadly described ascomprising a regeneration blower assembly connected between a heaterplenum and a fresh air inlet duct of the HVAC system whereby air warmedin the heater plenum is directed through the odor absorbent where itentrains odors before being discharged through the fresh air inlet ofthe HVAC system. The apparatus also includes a controller.

More specifically, the regeneration blower assembly includes a blowerfan controlled by the controller. In addition, the regeneration blowerassembly includes a regeneration door displaceable between an openedposition and a closed position in response to the controller. Stillfurther, the regeneration blower assembly includes a first ductconnecting the blower fan with the heater plenum and a second ductconnecting the blower fan with the fresh air inlet duct.

Still further, the controller is operatively connected to a fresh airinlet door of the HVAC system. It should be appreciated, the controlleris configured to open the regeneration door, open the fresh air inletdoor and activate the blower fan for a predetermined period of time whenthe ignition system of the motor vehicle is switched off. Morespecifically, air from the passenger cabin of the motor vehicle is drawnby the blower fan through the heater plenum where that air is warmed.Next, the fan draws the warmed air through the first duct so that itpasses the blower fan and is then forced by the blower fan through thesecond duct and the odor absorbent. The warmed air regenerates the odorabsorbent which releases the odors, entraining them into the air stream.The air stream containing the entrained odors is then discharged fromthe fresh air inlet to the ambient environment outside of the motorvehicle.

Still further, the controller is configured to close the regenerationdoor, close the fresh air inlet door and deactivate the blower fan afterthe predetermined period of time has elapsed.

In accordance with an additional aspect, a motor vehicle is providedequipped with the apparatus just described.

In accordance with still another aspect, a method is provided forregenerating an odor absorbent in an HVAC system of a motor vehicle. Themethod may be broadly described as comprising the step of heating andregenerating the odor absorbent using heat from a heater core of theHVAC system.

More specifically, the method includes performing the heating andregenerating for a predetermined period of time after the ignitionsystem of the motor vehicle is switched off. Further, the methodincludes using a dedicated blower fan to draw air through a heaterplenum of the HVAC system and then force that air through the odorabsorbent to regenerate the odor absorbent. Still further, the methodincludes discharging the air and odors entrained therein through a freshair inlet of the HVAC system.

More specifically, the method also includes the step of opening aregeneration door leading to the blower fan and opening the fresh airinlet door prior to energizing the blower fan for heating andregenerating. Still further, the method includes closing theregeneration door, closing the fresh air inlet door and deenergizing theblower fan after the predetermined period of time has elapsed. Stillfurther, the method includes utilizing a controller to open and closethe regeneration door and the fresh air inlet door and energizing anddeenergizing the blower fan.

In the following description, there are shown and described severalpreferred embodiments of the regeneration apparatus and method. As itshould be realized, the regenerating apparatus and method are capable ofother, different embodiments and their several details are capable ofmodification in various, obvious aspects all without departing from theregeneration apparatus and method as set forth and described in thefollowing claims. Accordingly, the drawings and descriptions should beregarded as illustrative in nature and not as restrictive.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

The accompanying drawing figures incorporated herein and forming a partof the specification, illustrate several aspects of the regenerationapparatus and method and together with the description serve to explaincertain principles thereof. In the drawing figures:

FIG. 1a is a schematic illustration of a motor vehicle HVAC systemincluding the regeneration apparatus that is the subject matter of thisdocument.

FIG. 1b is a schematic illustration of the control system for theregeneration apparatus illustrated in FIG. 1 a.

FIGS. 2a-2c are an operations flowchart for the apparatus to aid inillustrating the method that is the subject matter of this document.

FIG. 3 is a schematic illustration that shows various alternativepositions for connection of the first or takeoff duct of theregeneration apparatus to the heater plenum of the motor vehicle HVACsystem.

Reference will now be made in detail to the present preferredembodiments of the regeneration apparatus and method, examples of whichare illustrated in the accompanying drawing figures.

DETAILED DESCRIPTION

Reference is now made to FIGS. 1a and 1b , which schematicallyillustrate the apparatus 10 for regenerating an odor absorbent, such asactivated carbon, in a motor vehicle HVAC system, generally designatedby reference number 12. That HVAC system 12 includes an inlet duct 14having a fresh air inlet opening 16, a circulation fan 18 held in a fanhousing 20 and powered by a fan motor 22, a ventilation manifold 24 fordelivering air from the circulation fan 18 to the heater plenum 26 andduct work 28 to deliver treated air to various outlet vents 30 whichdeliver that air to the passenger cabin of the motor vehicle. Aparticulate air filter 32, including an odor absorbent such as activatedcarbon, is provided in the inlet duct 14 between the fresh air inletopening 16 and the fan housing 20. Thus, air being drawn into the HVACsystem 12 of the motor vehicle through the fresh air inlet opening 16passes through the air filter 32 before being forced by the circulationfan 18 into the cabin of the motor vehicle. This allows odors to bewithdrawn from the airstream and captured by the odor absorbent providedin the particulate filter 32 so that those odors are prevented fromreaching the occupants of the motor vehicle in the passenger cabin.

The regeneration apparatus 10 that is the subject matter of thisdocument includes a regeneration blower assembly generally designated byreference number 34. As illustrated in FIG. 1a , that regenerationblower assembly 34 is connected between the heater plenum 26 and thefresh air inlet duct 14 of the HVAC system 12.

More specifically, the regeneration blower assembly 34 includes adedicated regeneration blower fan 36 held in a fan compartment 38. Afirst duct 40 connects the blower fan 36 and the fan compartment 38 withthe heater plenum 26, while a second duct 42 connects the blower fan 36with the fresh air inlet duct 14. In addition, the regeneration blowerassembly 34 also includes a regeneration door 44 that is displaceablebetween an opened position and a closed position in order to control theflow of air between the first duct 40 and the fan compartment 38. TheHVAC system 12 includes a similar door, the fresh air inlet door 48 thatis utilized to open and close the fresh air inlet opening 16.

As illustrated in FIG. 1b , the regeneration apparatus 10 also includesa controller 50. The controller 50 may take the form of a dedicatedmicroprocessor, computing device or electronic control unit (ECU). Thus,the controller 50 may comprise one or more processors, one or morememories and one or more network interfaces that all communicate witheach other over a communication bus.

The controller 50 includes a first data input 52 for receiving datarespecting the status of the ignition system of the motor vehicle. Thecontroller 50 also includes a second data input 54 for receiving datarespecting the revolutions being turned by the engine that powers themotor vehicle.

In addition, the controller 50 includes a third data input 56 receivingdata respecting the occupancy of the motor vehicle. Occupancy statusdata may be provided by the status of the vehicle door locks, seatbeltsensors, seat occupancy sensors including pressure sensors in the seats,infrared sensors, internal vehicle cameras for monitoring the presenceof motor vehicle occupants or the like.

Still further, the controller 50 also includes a fourth data input 58for monitoring the charge status of the battery of the motor vehicle. Inaddition, the controller 50 also includes an internal timer 60.

As further illustrated in FIG. 1b , the controller 50 is operativelyconnected through the control line 62 to a regeneration door actuator 64that displaces the regeneration door 44 between open and closedpositions. As further illustrated, the controller 50 is also connectedthrough the control line 66 to a fresh air inlet door actuator 68. Thefresh air inlet door actuator 68 functions to displace the fresh airinlet door 48 between open and closed positions.

As is also illustrated in FIG. 1b , the controller 50 is connected viathe control line 70 to the dedicated regeneration blower fan 36. Thecontroller 50 is configured to open the regeneration door 44, open thefresh air inlet door 48 and activate the regeneration blower fan 36 fora predetermined period of time based upon the operation of the timer 60when the ignition system of the motor vehicle is switched off so thatair from the passenger cabin of the motor vehicle is drawn through theheater plenum 26 where that air is warmed. Next, the regeneration blowerfan 36 draws that warmed air through the first duct 40 past the openregeneration door 44 into the fan compartment 38. The blower fan 36 thenforces that warmed air through the second duct 42 and through theparticulate air filter 32.

As the warmed air passes through the particulate air filter 32, thewarmed air comes into intimate contact with the odor absorbent. Heatfrom the warmed air causes the odor absorbent to release previouslyabsorbed odors which are then entrained in the air stream, therebyregenerating the odor absorbent. The air stream, which now entrains theodors, is then forced by the blower fan 36 past the open fresh air inletdoor 48 through the fresh air inlet opening 16 into the ambientenvironment outside of the motor vehicle passenger cabin. Thus, itshould be appreciated that odors are prevented from outgas sing into thepassenger cabin through the HVAC system.

As should be further appreciated, the controller 50 is also configuredto close the regeneration door 44, close the fresh air inlet door 48 anddeactivate the dedicated blower fan 36 after the predetermined period oftime measured by the internal timer 60 has elapsed.

As should be appreciated, the regeneration apparatus 10 operates inaccordance with a method for regenerating odor absorbent in an HVACsystem of a motor vehicle. That method may be broadly described asincluding the step of heating and regenerating the odor absorbent usingheat from a heater core or plenum of the HVAC system. More specifically,the method may be described as including the step of performing theheating and regenerating for a predetermined period of time after anignition system of the motor vehicle is switched off. Further, themethod may include using a dedicated blower fan 36 to draw air throughthe heater plenum 26 of the HVAC system 12 and then forcing that airthrough the odor absorbent to regenerate the odor absorbent. Stillfurther, the method may include discharging the air and odors entrainedtherein through the fresh air inlet opening 16 of the HVAC systemfollowing regeneration. Thus, it should be appreciated that the methodincludes opening a regeneration door 44 leading to the blower fan 36 andopening the fresh air inlet door 48 prior to energizing the blower fan36 for heating and regenerating. Further, the method includes closingthe regeneration door 44 and closing the fresh air inlet door 48 anddeenergizing the blower fan 36 after the predetermined time has elapsed.As described, all this is done utilizing the controller 50 which (a)opens and closes the regeneration door 44 and the fresh air inlet door48 by controlling operation of the door actuators 64, 68 and (b)energizes and deenergizes the motor of the blower fan 36.

Reference is now made to FIGS. 2a-2c which, taken together, illustrateone possible operations flowchart for the regeneration apparatus 10. Asillustrated in FIG. 2a , the regeneration method is initiated when thevehicle key is turned to the off position. This is indicated to thecontroller at the data input 52. The controller then monitors the datainputs 54 and 56 to confirm that the engine is shut off (engine RPM isequal to zero) and the vehicle is no longer occupied (indicated, forexample by one of the occupancy status data sources referenced above).Upon receiving confirmation that the engine is off and the passengercabin is unoccupied, the controller 50 initiates the regenerationprocess. Toward this end, the controller 50 determines whether the HVACsystem is in the tri-mode position wherein all outlet vents 30 includingthe window defroster vents, instrument panel vents and floor events areopen. If not, the controller 50 takes the necessary steps to open alloutlet vents 30 of the HVAC system 12 so as to allow the freest possibleflow of air between the motor vehicle cabin and the regeneration blowerfan 36.

As further illustrated in FIG. 2a , the controller 50 also checks thefourth data input 58 to confirm that the battery is at a sufficientvoltage or charge to allow operation of the regeneration apparatus 10without significant depletion of the battery.

Next, as illustrated in FIG. 2b , the controller 50 confirms the statusof the fresh air inlet door 48 and opens that door if it is closed bymeans of the fresh air inlet door actuator 68. Next, the controller 50opens the regeneration door 44 by means of the regeneration dooractuator 64.

Next, as illustrated in FIG. 2c , the controller 50 activates theregeneration blower fan 36 which is run for a predetermined period oftime based upon the timer 60. When the predetermined period of time haselapsed, the controller 50 deactivates the regeneration blower fan 36and closes the regeneration door 44 through operation of theregeneration door actuator 64. The regeneration program is then stopped.However, it should be appreciated that for certain applications andsystems, the controller 50 would also close the fresh air inlet door 40if it had been previously closed prior to the initiation of theregeneration program.

Reference is now made to FIG. 3 which is a detailed cross-sectional viewof the heater plenum 26. Reference letter A illustrates a preferredposition for the connection of the first duct 40 of the regenerationapparatus 10 in the heater plenum 26 just upstream from the heater core72 while the reference letter B illustrates a preferred position for thetemperature blend door during the regeneration process.

Reference letter C illustrates two possible alternative positions forconnection of the first duct 40 to the heater plenum 26. When the firstor intake duct 40 is at either of the positions C, it is preferred thatthe temperature blend door be positioned as illustrated at referenceletter D.

The foregoing has been presented for purposes of illustration anddescription. It is not intended to be exhaustive or to limit theembodiments to the precise form disclosed. Obvious modifications andvariations are possible in light of the above teachings. All suchmodifications and variations are within the scope of the appended claimswhen interpreted in accordance with the breadth to which they arefairly, legally and equitably entitled.

What is claimed:
 1. An apparatus for regenerating an odor absorbent in a motor vehicle HVAC system, comprising: a regeneration blower assembly connected between a heater plenum and a fresh air inlet duct of said HVAC system whereby air warmed in said heater plenum is directed through said odor absorbent and then discharged through a fresh air inlet of said HVAC system.
 2. The apparatus of claim 1, further including a controller.
 3. The apparatus of claim 2, wherein said regeneration blower assembly includes a blower fan controlled by said controller.
 4. The apparatus of claim 3, wherein said regeneration blower assembly includes a regeneration door displaceable between an opened position and a closed position in response to said controller.
 5. The apparatus of claim 4, wherein said regeneration blower assembly includes a first duct connecting said blower fan with said heater plenum and a second duct connecting said blower fan with said fresh air inlet duct.
 6. The apparatus of claim 5, wherein said controller is operatively connected to a fresh air inlet door of said HVAC system.
 7. The apparatus of claim 6, wherein said controller is configured to open said regeneration door, open said fresh air inlet door and activate said blower fan for a predetermined period of time when an ignition system of said motor vehicle is switched off so that air from a passenger cabin of said motor vehicle is drawn through said heater plenum where said air is warmed, drawn through said first duct to said blower fan and then forced by said blower fan through said second duct and said odor absorbent, regenerating said odor absorbent and then discharged from said fresh air inlet.
 8. The apparatus of claim 6, wherein said controller is configured to open said regeneration door, open said fresh air inlet door and activate said blower fan for a predetermined period of time when an ignition system of said motor vehicle is switched off and a passenger cabin of said motor vehicle is unoccupied so that air from said passenger cabin of said motor vehicle is drawn through said heater plenum where said air is warmed, drawn through said first duct to said blower fan and then forced by said blower fan through said second duct and said odor absorbent, regenerating said odor absorbent and then discharged from said fresh air inlet
 9. The apparatus of claim 8, wherein said controller is configured to close said regeneration door, close said fresh air inlet door and deactivate said blower fan after said predetermined period of time has expired.
 10. A motor vehicle equipped with the apparatus of claim
 1. 11. A method for regenerating an odor absorbent in an HVAC system of a motor vehicle, comprising: heating and regenerating said odor absorbent using heat from a heater core of said HVAC system.
 12. The method of claim 11, including performing said heating and regenerating for a predetermined period of time after an ignition system of said motor vehicle is switched off.
 13. The method of claim 11, including performing said heating and regenerating for a predetermined period of time after an ignition system of said motor vehicle is switched off and a passenger cabin of said motor vehicle is determined to be unoccupied.
 14. The method of claim 13, including using a dedicated blower fan to draw air through a heater plenum of said HVAC system and then force that air through said odor absorbent to regenerate said odor absorbent.
 15. The method of claim 14, including discharging said air and odors entrained therein through a fresh air inlet of said HVAC system following regeneration.
 16. The method of claim 15, including opening a regeneration door leading to said blower fan and opening a fresh air inlet door prior to energizing said blower fan for heating and regenerating.
 17. The method of claim 16, including closing said regeneration door, closing said fresh air inlet door and deenergizing said blower fan after said predetermined time has expired.
 18. The method of claim 17, including utilizing a controller to open and close said regeneration door and said fresh air inlet door and energize and deenergize said blower fan. 